NEW YORK (AP) -- A roaring crowd. A newcomer to a suddenly potent lineup. A stingy pitching staff. The Washington Nationals are finding it's not so easy coming into Citi Field anymore.

They could find themselves out of sole possession of first place, too, if they don't figure out a way to break though against these new-look Mets.

Washington wasted an early two-run lead Saturday night, losing 3-2 to New York behind Lucas Duda's two homers and a tiebreaking double.

"It's been a long time since we've come to play the Mets and they've had a packed stadium. It's good for baseball. It makes it fun," Jayson Werth said. "I don't think it adds any pressure or anything like that. It just makes it for an exciting night of baseball and a good atmosphere. We welcome the challenge."

The Nationals ran off 12 straight wins at Citi Field, a streak that ended last September. The Mets have won the first two games in this series to secure a home series win against Washington for the first time since April 19-21, 2013.

With their second straight late win, the Mets moved one game behind Washington in the NL East with one game remaining in the series.

Playing for the first time since being acquired from Detroit on Friday at the non-waiver trade deadline, righty swinging Yoenis Cespedes was walked by left-handed reliever Matt Thornton (1-1) to face Duda, a lefty bat, even though Duda had already homered twice off Joe Ross on fireworks night and has been on a recent tear.

"We have confidence in (Thornton) every time he faces a lefty," Nationals manager Matt Williams said. "You get an opportunity to get him back in there tomorrow, we'll do it."

With 42,996 fans on their feet and cheering, Duda drove a 1-2 pitch the opposite way to left field that short-hopped the wall. Curtis Granderson, who doubled leading off the inning, scored to put New York ahead.

New York fell behind in the first on Ian Desmond's two-run single off Jacob deGrom, tiring the Mets All-Star with long at-bats in a 31-pitch inning. But deGrom held the Nationals through six innings, even without his best fastball.

Hansel Robles (3-2) struck out Bryce Harper and Werth in the eighth for the win.

Jeurys Familia was perfect in the ninth for his 28th save, striking out Michael Taylor with the elated crowd stand and chanting "Let's go Mets!" for the final out.

Ross held New York without a hit until Duda sent a shot to center field with two outs in the fourth. Duda then homered to left field leading off the seventh for his eighth longball in seven days - three multihomer games.

"Both home runs, they were OK pitches, I wouldn't say down the middle by any means." Ross said. "I guess I kind of learned my lesson, be a little bit more careful next time. He had a helluva game."

Four days earlier, Duda hit one of his three homers in the game against the Padres off Joe's brother Tyson Ross.

Joe Ross allowed only two other hits in 6 1-3 innings.

"Those guys are filthy - two pretty exceptional pitchers," Duda said.

Cespedes batted third and received a polite standing ovation when he came to the plate in the first. He grounded out in his first two at-bats. But he got a rise out of the crowd in the sixth when he hit a long flyball to left that went foul. He struck out. He was 0 for 3 with the walk.

TRAINER'S ROOM

Nationals: Denard Span (back spasms) took 30 swings off a tee, his first swings in three weeks, he said. He also said he lifted weights and ran sprints for first time in last couple of days. He says he felt good but the test will be how he feels in the days after the workouts. "I still have a long road ahead of me," Span said.

Mets: 3B David Wright (back) will travel with the team to Miami and continue his workouts, manager Terry Collins says. He should then go to the club's complex in Port St. Lucie, Florida, where he will soon begin rehab games. "I don't think there is any question David Wright will play again this summer," Collins said.

UP NEXT

Nationals: Jordan Zimmermann has faced the Mets more than any other opponent, 22 games, and he is 8-5 with a 2.96 ERA.

Mets: Rookie Noah Syndergaard is coming off his best start as a big leaguer. He retired his first 18 batters and finished by allowing only three hits. In his only game against the Nationals, the right-hander faced Bryce Harper three times and gave up two hits.